The utility of low velocity liquid sprays substantially comprised of submicron sized liquid droplets is well known and includes applications ranging from combustion processes to delivery systems for medicines. As a reference, see "Atomization and Sprays" by Arthur H. Lefebvre, Hemisphere Publishing Corporation, New York.
A number of types of devices exist for generating small liquid droplets, including pressure, rotary, or twin-fluid type, some of which utilize electrostatic, ultrasonic or other type of excitation. For an example of devices utilizing piezoelectric elements, see U.S. Pat. Nos. 5,145,113 and 5,152,457, both to Burwell et al., and both incorporated herein by reference. Many of these devices are particularly complicated and/or contain high maintenance or unreliable parts. For example, piezoelectric components are notoriously maintenance intensive, unreliable and expensive. Consequently, known spray generation devices must be designed with the piezoelectric elements accessible for maintenance and/or replacement purposes. In addition, devices currently available operate almost exclusively in the vertical or upright position, which limits their usefulness.
It is therefore desirable to develop a device utilizing impaction technology for generating liquid sprays substantially comprised of submicron sized liquid droplets at relatively high flow rates and low velocities. It is also desirable to develop a device for generating such liquid sprays which is effective in the vertical direction, and in all other orientations. It is further desirable to develop a device utilizing components of simple, reliable and inexpensive construction. The present invention is directed toward such a device.